Counter cross flow for automatic processors

Abstract: Described herein ia low volume photographic material processing apparatus which utilizes a narrow horizontal processing channel (25) which is formed by a repeating combination of transport roller units (12, 13, 15) and impingement slot nozzles. Photographic processing solution is introduced into opposite ends of alternating impingement slot nozzles and the roller units (12, 13, 15) are used to remove processing solution from the photosensitive material (21) and provide transport therefor. The slot nozzles and the roller units (12, 13, 15) work interactively to break down the chemical barrier layer over the surface of the photosensitive material (21).

Description: Field of the Invention The invention relates to automatic processors for processing photosensitive material, and is more particularly concerned with counter cross flow in such processors. Background of the Invention The processing of photosensitive material involves a series of steps such as developing, bleaching, fixing, washing, and drying. With the development step being the most critical and sensitive to variations induced by time, temperature, agitation and chemical activity. These steps lend themselves to mechanization by conveying a continuous web of film or cut sheets of film or photographic paper sequentially through a series of stations or tanks, each one containing a different processing liquid appropriate to the process step at that station. There are various sizes of photographic film processing apparatus, i.e., large photofinishing apparatus and microlabs. A large photofinishing apparatus utilizes tanks which contain approximately 100 liters of each processing solution. A small photofinishing apparatus or microlab utilizes tanks which may contain less than 10 liters of processing solution. The chemicals contained in the processing solution: cost money to purchase; change in activity and are seasoned by the constituents of the photosensitive materials which leach out during the photographic process; and after the chemicals are used the chemicals must be disposed of in an environmentally safe manner. Thus, it is important in all sizes of photofinishing apparatus to reduce the volume of processing solution. The prior art suggests various types of replenishing systems which add or subtract specific chemicals to the processing solution to maintain a consistency of photographic characteristics in the material developed. It is possible to maintain reasonable consistency of photographic characteristics only for a certain period of replenishment. After a processing solution has been used a given number of times, the solution is discarded and a new processing solution is added to the tank. Activity degradation due to instability of the chemistry, or chemical contamination, after the components of the processing solution are mixed together causes one to discard the processing solution in smaller volume tanks more frequently than larger volume tanks. Some of the steps in the photographic process utilize processing solutions which contain chemicals that are unstable, i.e., they have a short process life. Thus, processing solutions in tanks which contain unstable chemicals are discarded more frequently than processing solutions in tanks which contain stable chemicals. EP-A-0 424 824 is directed to a photographic apparatus wherein a photosensitive material is passed through a plurality of fluid suspension sections. Each of the sections include a tank for holding a reservoir of processing solution. U.S. Patent 5,179,404 discloses a processing apparatus wherein a narrow processing channel is formed between a rack and a tank. The photosensitive material is transported through the narrow channel by appropriate rollers contained in the rack and tank. Problems to be Solved by the Invention The prior art used automatic photoprocessing equipment to process photosensitive material. Automatic photoprocessing equipment typically is configured as a sequential arrangement of transport racks submerged in tanks filled with volumes of processing solutions. The shape and configuration of the racks and tanks is inappropriate in certain environments, for instance: offices, homes, computer areas, etc. The reason for the above is the potential damage to the equipment and the surroundings which may occur from spilled photographic processing solutions and the lack of facilities, i.e., running water and sinks to clean the racks and flush out the tanks. Photographic materials may become jammed in the processing equipment. In this situation the rack must be removed from the tank to gain access to the jammed photographic material in order to remove the jammed material. The shape and configuration of the racks and tanks made it difficult to remove a rack from a tank without spilling any processing solution. The configuration of the rack and the tank is primarily due to the need to constantly provide active processing solution to the photosensitive material. One of the primary functions of a rack and tank processor is to provide the proper agitation of the processing solution. Proper agitation will send fresh processing solution to the surface or surfaces of the photosensitive material, while removing the exhausted processing solution from the photosensitive material. The prior art suggests that if the volume of the various tanks contained within various sizes of photographic processing apparatus were reduced the same amount of film or photographic paper may be processed, while reducing the volume of processing solution which was used and subsequently discarded. One of the problems in using smaller volume tanks is to provide sufficient and consistent agitation of the processing solution to provide process uniformity across the photosensitive material. The prior art also used alternative techniques to remove exhausted processing solution from the surface or surfaces of the photosensitive material and to provide fresh processing solution to the surface or surfaces of the photosensitive material. These techniques include rotating patterned drums, mesh screens, squeegee blades and solution jets, etc. Mesh screens and rotating drums work well in removing exhausted processing solution and supplying fresh processing solution. Mesh screens, squeegee blades and drums may damage the delicate surface or surfaces of the photosensitive material with debris that accumulates within the mesh, on the blade, or on the drum surface. An additional problem with the rotating drum is that the rotating drum is large and thus limits the minimum size of the processing equipment. A further problem with a rotating drum is that it can only process one sheet of photosensitive material at a time. The problem of non-uniform processing of the photosensitive material is exacerbated when the widely spaced non-arrayed solution jets are used in close proximity to the photosensitive material. Solution jets also provide a method for removing and supplying fresh processing solution to and from the surface or surfaces of the photosensitive material. However, if one used solution jets in the form of widely spaced non-arrayed jets or holes to distribute fresh processing solution in small volume processing tanks, the photosensitive material would not be uniformly developed. The reason for the above is that when the fresh processing solution was distributed, the fresh processing solution was close to the photosensitive material and did not have space to uniformly spread out across the surfaces of the photosensitive material. If the distance between the widely arrayed jets or holes and the surface of the photosensitive material were increased to obtain adequate distribution of the fresh processing solution, one would no longer have a small volume tank. Slots were not used by the prior art to distribute fresh processing solution in large volume tanks since the processing solution would not travel uniformly across a large volume of solution. As the photosensitive material passes through the tank, a boundary layer is formed between the surfaces of the photosensitive material and the processing solution. The processing solution moves with the photosensitive material. Thus, the boundary layer between the photosensitive material and the processing solution has to be broken up to enable fresh processing solution to reach the photosensitive material. Rollers were used in large prior art tanks to break up the boundary layer. The roller squeegeed the exhausted processing solution away from the surfaces of the photosensitive material, thus, permitting fresh processing solution to reach the surfaces of the photosensitive material. One would not use only closely spaced rollers in small volume tanks, to break the boundary layer between the photosensitive material and the processing solution, since rollers require additional space and add to the volume of required processing solution. A further problem with existing processors is that the processor may only process, at a given time, photosensitive material in a roll or cut sheet format. In addition, processors that are configured to process photosensitive material in a cut sheet format, may be limited in their ability to process the photosensitive material, by the minimum or maximum length of the photosensitive material, which may be transported. Additional rollers are required to transport shorter photosensitive material lengths. The reason for this is that, a portion of the photosensitive material must always be in physical contact with a pair of transporting rollers, or the cut sheet of photosensitive material will fail to move through the entire processor. As the number of required transport rollers increases, the agitation of the processing solution decreases. Even though the rollers remove processing solution and hence, break up the boundary layer, the additional rollers severely impede the flow of fresh processing solution to and exhausted processing solution from the surface of the photosensitive material. Certain photosensitive materials and processing solutions are more uniformly sensitive to variations in the fluid dynamics of processing solution impingement on the photosensitive material. For example when the photosensitive material is developed the photosensitive material may have non-uniform density. Summary of the Invention This invention overcomes the disadvantages of the prior art by providing a low volume photographic material processing apparatus that introduces fresh processing solution uniformly across the surfaces of a photosensitive material. In accordance with one aspect of the present invention, there is provided apparatus for processing photosensitive materials, the apparatus comprising:- at least one processing module each comprising a container, at least one processing assembly placed in the container, said processing assembly having a processing channel formed within said assembly through which a processing solution flows, the processing channel having an entrance through which the photosensitive material enters the processing channel and an exit through which the photosensitive material exits the channel, the processing channel comprises at least 40% of the total volume of processing solution available to the processing module; transport means for transporting the photosensitive material from the channel entrance through the processing channel to the channel exit, and at least one outlet for allowing the processing solution to exit the processing channel; recirculating means is provided for circulating the processing solution from each outlet through the processing channel in the container; at least two slot nozzles are operable for introducing processing solution into the processing channel, for controlling the velocity and amount of processing solution which dynamically impinges on the surface of the photosensitive material. The processing apparatus utilizes a slot nozzle configuration, whose fluid distribution pattern meets or exceeds the width of the photosensitive material. The slot nozzle does not have to be periodically changed or cleaned and is designed in such a manner that an amount of fresh processing solution exits the slot nozzle at a sufficient velocity to disrupt the boundary layer of exhausted processing solution allowing fresh processing solution to reach the surfaces of the photosensitive material. The slot nozzle permits the velocity of the exiting processing solution to be varied by changing the pressure of the solution. Thus, the amount of fresh processing solution reaching the surfaces of the photosensitive material may be controlled. Hence, the chemical reaction between the photosensitive material and the fresh processing solution reaching the surface of the photosensitive material may be controlled. Additional slot nozzles may be utilized to control the amount of chemical reaction between the fresh processing solution and the photosensitive material. When uniformly sensitive, photosensitive materials and processing solutions are used a series of slot nozzles that have alternating flow patterns may be used to provide for uniform development. The alternating flow patterns are created by introducing processing solution into opposite ends of alternating slot nozzles. Advantageous Effect of the Invention The above arrangements of solution impingement slot nozzles provide fresh processing solution to the photosensitive material while removing exhausted processing solution from the photosensitive material. The act of alternating the flow patterns of processing solution by introducing processing solution into opposite ends of alternating slot nozzles, having corresponding tapered delivery channels, compensates for non-uniform processing solution delivery inadvertently introduced during single direction flow. The foregoing may arise as solution filters become clogged during use reducing processing solution flow, or processing solution viscosity changes, or precipitation of the processing solution that creates restrictions to flow, or variations introduced by tolerances in the manufacture of the slot nozzle. Brief Description Of The Drawings For a better understanding of the present invention, reference will now be made, by way of example only, to the accompanying drawings in which:- Figure 1 is a perspective view of a processing module constructed in accordance with the present invention and which forms part of a tray processor; Figure 2 is a partially sectioned view of the module shown in Figure 1 illustrating one embodiment of a processing module according to the present invention for processing material having one emulsion surface; Figure 3 is a partially sectioned view similar to that shown in Figure 2, but of a second embodiment of a processing module according to the present invention; Figure 4 is a partially sectioned view similar to that shown in Figure 2, but of a third embodiment of a processing module according to the present invention for processing material having two emulsion surfaces; Figure 5 is a schematic view of a processing solution recirculation system of the apparatus in accordance with the present invention; Figure 6 is a perspective view of a plurality of slot nozzle illustrating counter cross flow; and Figure 7 is a perspective view of an alternate embodiment of a slot nozzle. Detailed Description of the Invention Referring now to the drawings in detail, and more particularly to Figure 1, the reference character 10 represents a processing module, which may stand alone or be easily combined or adjoined with other processing modules 10 to form a continuous low volume unit for processing photosensitive materials. Processing module 10 includes: a container 11; an upturned entrance channel 100 (described in the description of Figure 2); an entry transport roller assembly 12; transport roller assemblies 13; an exit transport roller assembly 15; an upturned exit channel 101 (described in the description of Figure 2); high impingement slot nozzles 17a, 17b and 17c; a drive 16 and a rotating assembly 18, assembly 18 may be any known means for turning drive 16, i.e., a motor, a gear, a belt, a chain, etc. An access hole 61 is provided in container 11. Hole 61 is utilized for the interconnection of modules 10. Assemblies 12, 13 and 15 and slot nozzles 17a, 17b and 17c are positioned within the vicinity of the walls of container 11. Drive 16 is connected to roller assemblies 12, 13 and 15 and turning assembly 18 and assembly 16 is used to transmit the motion of assembly 18 to assemblies 12, 13 and 15. Roller assemblies 12, 13, and 15, and slot nozzles 17a, 17b and 17c may be easily inserted into or removed from container 11. Roller assembly 13 includes: a top roller 22; a bottom roller 23; tension springs 62, which holds top roller 22 in compression with respect to bottom roller 23; a bearing bracket 26; and a channel section 24 having a thin low volume processing channel 25. A narrow channel opening 27 (Figure 2) exists within section 24. Opening 27 on the entrance side of section 24 may be the same size and shape as opening 27 on the exit side of section 24. Opening 27 on the entrance side of section 24 may also be relieved, tapered or larger than the exit side of section 24 to accommodate rigidity variations of various types of photosensitive material 21. Channel opening 27 forms a portion of processing channel 25. Rollers 22 and 23 may be drive or driven rollers and are connected to bracket 26. Rollers 22 and 23 are rotated by intermeshing gears 28. Photosensitive material 21 is transported in either direction A or direction B automatically through processing channel 25 by roller assemblies 12, 13 and 15. Photosensitive material 21 may be in a cut sheet or roll format or photosensitive material 21 may be simultaneously in a roll and simultaneously in a cut sheet format. Photosensitive material 21 may contain an emulsion on either or both of its surfaces. When cover 20 is placed on container 11 a light tight enclosure is formed. Thus, module 10 with its associated recirculation system 60, which is described in the description of Figure 5, will be a stand alone light tight module which is capable of processing photosensitive material, i.e., a monobath. When two or more modules 10 are combined a multi-stage continuous processing unit may be formed. Figure 2 is a partially sectioned view of module 10 shown in Figure 1. Assemblies 12, 13 and 15, nozzles 17a, 17b and 17c and backing plate 9 are designed in a manner to minimize the amount of processing solution which is contained in processing channel 25, vessel 11, recirculation system 60 (Figure 5) and gaps 49a, 49b, 49c and 49d. At the entrance of module 10, an upturned channel 100 forms the entrance to processing channel 25. At the exit of module 10, an upturned channel 101 forms the exit to processing channel 25. Assembly 12 is similar to assembly 13. Assembly 12 includes: a top roller 30; a bottom roller 31; tension springs 62 (not shown) which holds top roller 30 to bottom roller 31; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 is formed by channel section 24. Rollers 30 and 31 may be drive or driven rollers and are connected to bracket 26. Assembly 15 is similar to assembly 13, except that assembly 15 has an additional two rollers 130 and 131, which operate in the same manner as rollers 32 and 33. Assembly 15 includes: a top roller 32; a bottom roller 33; tension springs 62 (not shown); a top roller 130; a bottom roller 131; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 32, 33, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Backing plate 9 and slot nozzles 17a, 17b and 17c are affixed to container 11. The embodiment shown in Figure 2 will be used when photosensitive material 21 has an emulsion on one of its surfaces. The emulsion side of material 21 will face slot nozzles 17a, 17b and 17c. Material 21 enters channel 25 between rollers 30 and 31 and moves past backing plate 9 and nozzle 17a. Then material 21 moves between rollers 22 and 23 and moves past backing plates 9 and nozzles 17b and 17c. At this point material 21 will move between rollers 32 and 33, and move between rollers 130 and 131 and exit processing channel 25. Conduit 48a connects gap 49a, via port 44a to recirculation system 60 via port 44 (Figure 5), which is more fully described in the description of Figure 5, and conduit 48b connects gap 49b, via port 45a to recirculation system 60 via port 45 (Figure 5). Conduit 48c connects gap 49c, via port 46a to recirculation system 60 via port 46 (Figure 5) and conduit 48d connects gap 49d, via port 47a to recirculation system 60 via port 47 (Figure 5). Slot nozzle 17a is connected to recirculation system 60 via conduit 50a and inlet port 41a via port 44 (Figure 5) and slot nozzle 17b is connected to recirculation system 60 via conduit 50b and inlet port 42a via inlet port 42 (Figure 5). Conduit 50c connects nozzle 17c, via inlet port 43a to recirculation system 60 via port 43 (Figure 5). Sensor 52 is connected to container 11 and sensor 52 is used to maintain a processing solution level 235 relative to conduit 51. Excess processing solution may be removed by overflow conduit 51. Textured surface 200 is affixed to the surface of backing plate 9 which faces processing channel 25 and to the surface of slot nozzles 17a, 17b and 17c that faces processing channel 25. Figure 3 is a partially sectioned view of an alternate embodiment of module 10 of Figure 2 in which material 21 has an emulsion on one surface and nozzles 17d, 17e and 17f are on the top portion of container 11. Assemblies 12, 13 and 15, nozzles 17d, 17e and 17f and backing plate 9 are designed in a manner to minimize the amount of processing solution which is contained in processing channel 25 and gaps 49e, 49f, 49g and 49h. At the entrance of module 10, an upturned channel 100 forms the entrance to processing channel 25. At the exit of module 10, an upturned channel 101 forms the exit to processing channel 25. Assembly 12 is similar to assembly 13. Assembly 12 includes: a top roller 30; a bottom roller 31; tension springs 62 (not shown) which holds top roller 30 in compression with respect to bottom roller 31, a bearing bracket 26; and a channel section 24. A portion of narrow channel opening 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 30 and 31 may be drive or driven rollers and are connected to bracket 26. Assembly 15 is similar to assembly 13, except that assembly 15 has an additional two rollers 130 and 131 which operate in the same manner as rollers 32 and 33. Assembly 15 includes: a top roller 32; a bottom roller 33; a tension spring 62 (not shown); a top roller 130; a bottom roller 131; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 32, 33, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Thus, it can be seen that a substantially continuous processing channel is provided. Backing plate 9 and slot nozzles 17d, 17e and 17f are affixed to container 11. The embodiment shown in Figure 3 will be used when photosensitive material 21 has an emulsion on one of its surfaces. The emulsion side of material 21 will face slot nozzles 17d, 17e and 17f. Material 21 enters channel 25 between rollers 30 and 31 and moves past backing plate 9 and nozzle 17d. Then material 21 moves between rollers 22 and 23 and moves past backing plates 9 and nozzles 17e and 17f. At this point material 21 will move between rollers 32 and 33 and move between rollers 130 and 131 and exit processing channel 25. Conduit 48e connects gap 49e, via port 44b to recirculation system 60 via port 44 (Figure 5) and conduit 48f connects gap 49f, via port 45b to recirculation system 60 via port 45 (Figure 5). Conduit 48g connects gap 49g, via port 46b to recirculation system 60 via port 46 (Figure 5) and conduit 48h connects gap 49h, via port 47b to recirculation system 60 via port 47 (Figure 5). Slot nozzle 17d is connected to recirculation system 60 via conduit 50d and inlet port 41b via inlet 41 (Figure 5) and slot nozzle 17e is connected to recirculation system 60 via conduit 50e and inlet port 42b via port 42 (Figure 5). Conduit 50f connects nozzle 17f, via inlet port 43b to recirculation system 60 via port 43 (Figure 5). Sensor 52 is connected to container 11 and sensor 52 is used to maintain a processing solution level 235 relative to conduit 51. Excess processing solution may be removed by overflow conduit 51. Textured surface 200 is affixed to the surface of backing plate 9 which faces processing channel 25 and to the surface of slot nozzles 17d, 17e and 17f which faces processing channel 25. Figure 4 is a partially sectioned view of an alternate embodiment of the processing module 10 shown in Figure 2 in which material 21 has an emulsion on both surfaces and nozzles 17g, 17h and 17i are on the top portion of container 11 facing one emulsion surface of material 21 and nozzles 17j, 17k, and 17L are on the bottom portion of container 11 facing the other emulsion surface of material 21. Assemblies 12, 13 and 15, nozzles 17g, 17h, 17i, 17j, 17k and 17L are designed in a manner to minimize the amount of processing solution which is contained in processing channel 25 and gaps 49i, 49j, 49k and 49L. At the entrance of module 10, an upturned channel 100 forms the entrance to processing channel 25. At the exit of module 10, an upturned channel 101 forms the exit to processing channel 25. Assembly 12 includes: a top roller 30; a bottom roller 31; tension springs 62 (not shown) which holds top roller 30 in compression with respect to bottom roller 31, a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 30, 31, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Assembly 15 is similar to assembly 13, except that assembly 15 has an additional two rollers 130 and 131 which operate in the same manner as rollers 32 and 33. Assembly 15 includes: a top roller 32; a bottom roller 33; tension springs 62 (not shown); a top roller 130; a bottom roller 131; a bearing bracket 26; and a channel section 24. A portion of narrow processing channel 25 exists within section 24. Channel section 24 forms a portion of processing channel 25. Rollers 32, 33, 130 and 131 may be drive or driven rollers and are connected to bracket 26. Slot nozzles 17g, 17h and 17i are affixed to the upper portion of container 11. Slot nozzles 17j, 17k and 17L are affixed to the lower portion of container 11. The embodiment shown in Figure 4 will be used when photosensitive material 21 has an emulsion on both of its two surfaces. One emulsion side of material 21 will face slot nozzles 17g, 17h and 17i and the other emulsion side of material 21 will face slot nozzles 17j, 17k and 17L. Material 21 enters channel 25 between rollers 30 and 31 and moves past and nozzles 17g and 17j. Then material 21 moves between rollers 22 and 23 and moves past nozzles 17h, 17k, 17i and 17L. At this point material 21 will move between rollers 32 and 33 and move between rollers 130 and 131 and exit processing channel 25. Conduit 48i connects gap 49i, via port 44c to recirculation system 60 via port 44 (Figure 5) and conduit 48j connects gap 49k, via port 45c to recirculation system 60 via port 45 (Figure 5). Conduit 48k connects gap 49L, via port 46c to recirculation system 60 and conduit 48L connects gap 49j, via port 47c to recirculation system 60 via port 47 (Figure 5). Slot nozzle 17g is connected to recirculation system 60 via conduit 50g via port 41 (Figure 5). Slot nozzle 17h is connected to recirculation system 60 via conduit 50h and inlet port 62 via port 42 (Figure 5). Conduit 50i connects nozzle 17i to recirculation system 60 via port 43 (Figure 5). Slot nozzle 17j is connected to recirculation system 60 via conduit 50j and inlet port 41c via port 41 (Figure 5) and slot nozzle 17k is connected to recirculation system 60 via conduit 50k and inlet port 42c via port 42 (Figure 5). Slot nozzle 17L is connected to recirculation system 60 via conduit 50L and inlet port 43c via port 43 (Figure 5). Sensor 52 is connected to container 11 and sensor 52 is used to maintain a processing solution level 235 relative to conduit 51. Excess processing solution may be removed by overflow conduit 51. Material 21 enters upturned channel entrance 100, then passes through channel section 24 of channel 25 between rollers 30 and 31 and moves past nozzles 17g and 17j. Then material 21 moves between rollers 22 and 23 and moves past nozzles 17h and 17k, 17L and 17i. At this point material 21 will move between rollers 32 and 33 and exit processing channel 25. Textured surface 200 is affixed to the surface of slot nozzles 17g, 17h, 17i, 17j, 17k and 17L which face processing channel 25. Figure 5 is a schematic drawing of the processing solution recirculation system 60 of the apparatus of this invention. Module 10 is designed in a manner to minimize the volume of channel 25. The outlets 44, 45, 46 and 47 of module 10 are connected to recirculating pump 80 via conduit 85. Recirculating pump 80 is connected to manifold 64 via conduit 63 and manifold 64 is coupled to filter 65 via conduit 66. Filter 65 is connected to heat exchanger 86 and heat exchanger 86 is connected to channel 25 via conduit 4. Control logic 67 is connected to heat exchanger 86 via wire 68. Control logic 67 is connected to heat exchanger 86 via wire 70 and sensor 52 is connected to control logic 67 via wire 71. Metering pumps 72, 73 and 74 are respectively connected to manifold 64 via conduits 75, 76 and 77. Thus, it can be seen that processing solution is pumped directly from the outlet passages to the inlet ports without use of a reservoir. The photographic processing chemicals which comprise the photographic solution are placed in metering pumps 72, 73 and 74. Pumps 72, 73 and 74 are used to place the correct amount of chemicals in manifold 64, when photosensitive material 210 sensor senses that material 21 (Figure 1) is entering channel 25. Sensor 210 transmits a signal to pumps 72, 73 and 74 via line 211 and control logic 67. Manifold 64 introduces the photographic processing solution into conduit 66. The photographic processing solution flows into filter 65 via conduit 66. Filter 65 removes contaminants and debris which may be contained in the photographic processing solution. After the photographic processing solution has been filtered, the solution enters heat exchanger 86. Sensor 52 senses the solution level and sensor 8 senses the temperature of the solution and respectively transmits the solution level and temperature of the solution to control logic 67 via wires 71 and 7. For example, control logic 67 is the series CN 310 solid state temperature controller manufactured by Omega Engineering, Inc. of 1 Omega Drive, Stamford, Connecticut 06907. Logic 67 compares the solution temperature sensed by sensor 8 and the temperature which exchanger 86 transmitted to logic 67 via wire 70. Logic 67 will inform exchanger 86 to add or remove heat from the solution. Thus, logic 67 and heat exchanger 86 modify the temperature of the solution and maintain the solution temperature at the desired level. Sensor 52 senses the solution level in channel 25 and transmits the sensed solution level to control logic 67 via wire 71. Logic 67 compares the solution level sensed by sensor 52 via wire 71 to the solution level set in logic 67. Logic 67 will inform pumps 72, 73 and 74 via wire 83 to add additional solution if the solution level is low. Once the solution level is at the desired set point control logic 67 will inform pumps 72, 73 and 74 to stop adding additional solution. Any excess solution may either be pumped out of module 10 or removed through level drain overflow 84 via conduit 81 into container 82. At this point the solution enters module 10 via inlets 41, 42 and 43. When module 10 contains too much solution the excess solution will be removed by overflow conduit 51, drain overflow 84 and conduit 81 and flow into reservoir 82. The solution level of reservoir 82 is monitored by sensor 212. Sensor 212 is connected to control logic 67 via line 213. When sensor 212 senses the presence of solution in reservoir 82, a signal is transmitted to logic 67 via line 213 and logic 67 enables pump 214. Thereupon, pump 214 pumps solution into manifold 64. When sensor 212 does not sense the presence of solution, pump 214 is disabled by the signal transmitted via line 213 and logic 67. When solution in reservoir 82 reaches overflow 215 the solution will be transmitted through conduit 216 into reservoir 217. The remaining solution will circulate through channel 25 and reach outlet lines 44, 45,46 and 47. Thereupon, the solution will pass from outlet lines 44, 45, 46 and 47 to conduit line 85 to recirculation pump 80. The photographic solution contained in the apparatus of this invention, when exposed to the photosensitive material, will reach a seasoned state more rapidly than prior art systems, because the volume of the photographic processing solution is less. Figure 6 is a perspective view of a plurality of slot nozzles 17. Slot 160 runs across surface 161 of slot nozzle 17. Conduit 162 connects slot 160 to inlets 41a, 42a, 43a (Figure 2), 41b, 42b, 43b (Figure 3) and 41c, 41d, 42c, 42d, 43c, 43d (Figure 4). Flange 108 of nozzle 17 is attached to container 11 by any known conventional means which will prevent the leaking of processing solution from container 11, e.g., gaskets, screws etc. Processing solution will enter inlet 41a, 41b, 41c, 41d, 42a, 42b, 42c, 42d, 43a, 43b, 43c, 43d proceed down narrowing conduit 162 with an ever increasing velocity providing a uniform flow of processing solution out of the entire length of slot 160. The width X of the processing solution exiting slot 160 is adequate to cover the width of the photosensitive material 21. The depth or thickness Y of slot 160 is such that Y/X(100) is less than 1. Slot 163 runs across surface 164 of slot nozzle 17. Conduit 165 connects slot 163 to inlets 41a, 42a, 43a (Figure 2), 41b, 42b, 43b (Figure 3) and 41c, 41d, 42c, 42d, 43c, 43d (Figure 4). Flange 108 of nozzle 17 is attached to container 11 by any known conventional means which will prevent the leaking of processing solution from container 11, e.g., gaskets, screws, etc. Processing solution will enter inlet 41a, 41b, 41c, 41d, 42a, 42b, 42c, 42d, 43a, 43b, 43c, 43d proceed down narrowing conduit 165 with an ever increasing velocity providing a uniform flow of processing solution out of the entire length of slot 163. The width X of the processing solution exiting slot 163 is adequate to cover the width of the photosensitive material 21. The depth or thickness Y of slot 163 is such that Y/X(100) is less than 1. Slot 166 runs across surface 167 of slot nozzle 17. Conduit 168 connects slot 166 to inlets 41a, 42a, 43a (Figure 2), 41b, 42b, 43b (Figure 3) and 41c, 41d, 42c, 42d, 43c, 43d (Figure 4). Flange 108 of nozzle 17 is attached to container 11 by any known conventional means which will prevent the leaking of processing solution from container 11, e.g., gaskets, screws, etc. Processing solution will enter inlet 41a, 41b, 41c, 41d, 42a, 42b, 42c, 42d, 43a, 43b, 43c, 43d proceed down narrowing conduit 168 with an ever increasing velocity providing a uniform flow of processing solution out of the entire length of slot 166. The width X of the processing solution exiting slot 166 is adequate to cover the width of the photosensitive material 21. The depth or thickness Y of slot 166 is such that Y/X(100) is less than 1. Slot 169 runs across surface 170 of slot nozzle 17. Conduit 171 connects slot 169 to inlets 41a, 42a, 43a (Figure 2), 41b, 42b, 43b (Figure 3) and 41c, 41d, 42c, 42d, 43c, 43d (Figure 4). Flange 108 of nozzle 17 is attached to container 11 by any known conventional means which will prevent the leaking of processing solution from container 11, e.g., gaskets, screws, etc. Processing solution will enter inlet 41a, 41b, 41c, 41d, 42a, 42b, 42c, 42d, 43a, 43b, 43c, 43d proceed down narrowing conduit 171 with an ever increasing velocity providing a uniform flow of processing solution out of the entire length of slot 169. The width X of the processing solution exiting slot 169 is adequate to cover the width of the photosensitive material 21. The depth or thickness Y of slot 169 is such that Y/X(100) is less than 1. Thus, processing solution exiting slots 160, 163, 166 and 169 of slot nozzles 17 will alternate in direction. Four slot nozzles 17 have been described above, it will be obvious to one skilled in the art that any even number of nozzles 17 may be utilized and that slots 160, 163, 166 and 169 may have different shapes. Figure 7 is a perspective view of an alternate embodiment of slot nozzle 17. Slots 120 and 121 run across surface 122 of slot nozzle 17. The orientation of slots 120 and 121 is determined by angles Z and Z'. Angles Z and Z' are between 0° and 89°. Narrowing conduit 124 is connected to slot 120 and conduit 124 is connected to manifold 125. Manifold 125 is connected to inlets 41a, 42a, 43a (Figure 2), 41b, 42b, 43b (Figure 3) and 41c, 41d, 42c, 42d, 43c, 43d (Figure 4). Conduit 127 connects manifold 125 to narrowing conduit 126. Flange 108 of nozzle 17 is attached to container 11 by any known conventional means which will prevent the leaking of processing solution from container 11, e.g., gaskets, screws, etc. Processing solution will enter inlet 41a, 41b, 41c, 41d, 42a, 42b, 42c, 42d, 43a, 43b, 43c, 43d proceed through manifold 125, and simultaneously proceed through narrowing conduit 124 and conduit 127. The processing solution traveling in conduit 124 will have an ever increasing velocity as the processing solution proceeds down conduit 124. This will provide a uniform flow of processing solution out of the entire length of slot 120. The processing solution traveling in conduit 127 will proceed through conduit 126 and have an ever increasing velocity as the processing solution proceeds down conduit 126. This will provide a uniform flow of processing solution out of the entire length of slot 121. Width X of slots 120 and 121 will be wider than the width of photosensitive material 21. The depth or thickness Y of slots 120 and 121 is such that Y/X(100) is less than 1. Other embodiments of slot nozzles are described in European publication no. 0 623 848, published 09 November 1994 and which claims priority from USSN 056649 filed 3 May 1993 and USSN 209755 filed 10 March 1994 and entitled Slot Impingement for Automatic Processors . A processor made in accordance with the present invention provides a small volume for holding processing solution. As a part of limiting the volume of the processing solution, a narrow processing channel is provided. The processing channel 25, for a processor used for photographic paper, should have a thickness t equal to or less than about 50 times the thickness of paper being processed, preferably the thickness t is equal to or less than about 10 times the paper thickness. In a processor for processing photographic film, the thickness t of the processing channel 25 should be equal to or less than about 100 times the thickness of photosensitive film, preferably, equal to or less than about 18 times the thickness of the photographic film. An example of a processor made in accordance with the present invention which processes paper having a thickness of about 0.2mm (0.008") would have a channel thickness t of about 2mm (0.080") and a processor which process film having a thickness of about 0.14mm (0.0055") would have a channel thickness t of about 2.54mm (0.10"). The total volume of the processing solution within the processing channel 25 and recirculation system 60 is relatively smaller as compared to prior art processors. In particular, the total amount of processing solution in the entire processing system for a particular module is such that the total volume in the processing channel 25 is at least 40% of the total volume of processing solution in the system. Preferably, the volume of the processing channel 25 is at least about 50% of the total volume of the processing solution in the system. In the particular embodiment illustrated, the volume of the processing channel is about 60% of total volume of the processing solution. Typically the amount of processing solution available in the system will vary on the size of the processor, that is, the amount of photosensitive material the processor is capable of processing. For example, a typical prior art microlab processor, a processor which processes up to about 0.46m 2 /min (5ft 2 /min) of photosensitive material (which generally has a transport speed less than about 1.27m/min (50" per minute) has about 17 liters of processing solution as compared to about 5 liters for a processor made in accordance with the present invention. With respect to typical prior art minilabs, a processor that processes from about 0.46m 2 /min (5ft 2 /min) to about 1.39m 2 /min (15ft 2 /min) of photosensitive material (which generally has a transport speed from about 1.27m/min (50in/min) to about 3.05m/min (120in/min)) has about 100 liters of processing solution as compared to about 10 liters for a processor made in accordance with the present invention. With respect to large prior art lab processors that process up to 4.6m 2 /min (50ft 2 /min) of photosensitive material (which generally have transport speeds of about 2.13 to 18m/min (7 to 60ft/min)) typically have from about 150 to 300 liters of processing solution as compared to a range of about 15 to 100 liters for a large processor made in accordance with the present invention. In a minilab size processor made in accordance with the present invention designed to process 1.39m 2 (15ft 2 ) of photosensitive material per minute would have about 7 liters of processing solution as compared to about 17 liters for a typical prior art processor. In certain situations it may be appropriate to provide a sump in the conduits 48a, 48b, 48c, 48d, 48e, 48f, 48g, 48h, 48i, 48j, 48k, 48L and/or gaps 49a, 49b, 49c, 49d, 49e, 49f, 49g, 49h, 49i, 49j, 49k, 49L so that vortexing of the processing solution will not occur. The size and configuration of the sump will, of course, be dependent upon the rate at which the processing solution is recirculated and the size of the connecting passages which form part of the recirculatory system. It is desirable to make the connecting passages as small as possible, yet, the smaller the size of the passages, for example, in the conduits 48a, 48b, 48c, 48d, 48e, 48f, 48g, 48h, 48i, 48j, 48k, 48L from the gaps 49a, 49b, 49c, 49d, 49e, 49f, 49g, 49h, 49i, 49j, 49k, 49L to the pump, the greater likelihood that vortexing may occur. For example, in a processor having a recirculatory rate of approximately 11.36 to 15.14l/min (3 to 4 US gallons/min), there is preferably provided a sump such that a head pressure of approximately 100mm (4") at the exit of the tray to the recirculating pump can be maintained without causing vortexing. The sump need only be provided in a localized area adjacent the conduits 48a, 48b, 48c, 48d, 48e, 48f, 48g, 48h, 48i, 48j, 48k, 48L of the tray. Thus, it is important to try to balance the low amount of volume of the processing solution available to the flow rate required of the processor. In order to provide efficient flow of the processing solution through the nozzles into the processing channel, it is desirable that the nozzles/openings that deliver the processing solution to the processing channel have a configuration in accordance with the following relationship: .586≤ F A ≤23.4 wherein: F is the flow rate of the solution through the nozzle in litres per minute; and A is the cross-sectional area of the nozzle provided in centimetres squared. Providing a nozzle in accordance with the foregoing relationship assures appropriate discharge of the processing solution against the photosensitive material. The above specification describes a new and improved apparatus for processing photosensitive materials. It is realized that the above description may indicate to those skilled in the art additional ways in which the principles of this invention may be used without departing from the scope of the claimed invention. It is, therefore, intended that this invention be limited only by the scope of the appended claims.

Claims: Apparatus for processing photosensitive materials (21), the apparatus comprising: at least one processing module (10) each comprising a container (11), at least one processing assembly (9, 17a, 17b, 17c, 17d, 17e, 17f, 17g, 17h, 17i, 17j, 17k, 17L) placed in the container (11), said processing assembly having a processing channel (25) formed within said assembly through which a processing solution flows, the processing channel (25) having an entrance (100) through which the photosensitive material enters the processing channel (25) and an exit (101) through which the photosensitive material exits the channel, the processing channel (25) comprising at least 40% of the total volume of processing solution available to the processing module (10); transport means (12, 13, 15) for transporting the photosensitive material (21) from the channel entrance (100) through the processing channel (25) to the channel exit (101), and at least one outlet (44a, 45a, 46a; 44b, 45b, 46b; 44c, 45c, 46c) for allowing the processing solution to exit the processing channel (25); recirculating means (64, 65, 80, 86, 226) provided for circulating the processing solution from each outlet (44a, 45a, 46a; 44b, 45b, 46b; 44c, 45c, 46c) through the processing channel (25) in the container (11); at least two slot nozzles (17a, 17b, 17c, 17d, 17e, 17f, 17g, 17h, 17i, 17j, 17k, 17L) are operable for introducing processing solution into the processing channel (25), for controlling the velocity and amount of processing solution which dynamically impinges on the surface of the photosensitive material (21). Apparatus according to claim 1, wherein the processing channel (25) comprises at least 60% of the total volume of the processing solution for the processing module. Apparatus according to claim 1 or claim 2, wherein the ratio of the length to the width of the first and second slot nozzle (17j, 17g, 17k, 17h, 17L, 17i) is such that the processing solution will rapidly and uniformly exit each slot nozzle (17j, 17g, 17k, 17h, 17L, 17i) . Apparatus according to any one of the preceding claims, wherein each slot nozzle (17j, 17g; 17k, 17h; 17L, 17i) has a configuration in accordance with the following relationship: .586≤ F A ≤23.4 wherein: F is the flow rate of the solution through the nozzle in litres per minute; and A is the cross-sectional area of the nozzle provided in centimetres squared. Apparatus according to claim 5, wherein the slot nozzles (17g, 17h, 17i, 17j, 17k, 17L) form part of the processing assembly (9, 17g, 17h, 17i, 17j, 17k, 17L). Apparatus according to claim 5 or 6, wherein the transport means (12, 13, 15) are disposed adjacent each processing assembly (9, 17g, 17h, 17i, 17j, 17k, 17L). Apparatus according to claim 7, wherein each processing assembly (9, 17g, 17h, 17i, 17j, 17k, 17L) and the transport means (12, 13, 15) form a substantially continuous processing channel (25) . Apparatus according to any one of the preceding claims, wherein the processing assembly (9, 17a, 17b, 17c, 17d, 17e, 17f, 17g, 17h, 17i, 17j, 17k, 17L) is removably mounted in the processing module (10). Apparatus according to claim 1 further comprising: a first conduit (162) which is connected to the first slot nozzle (160, 17a) and the recirculating means (44a, 80, 86, 41a) so that processing solution may travel in the first slot 160 in a first direction; and a second conduit (165) which is connected to a second slot nozzle (163, 17a) and the recirculation means (44a, 80, 86, 41a) so that processing solution may flow in the second slot of nozzle (17a) in a second direction. Apparatus according to any one of the preceding claims, wherein the processing module (10) is arranged such that the horizontal distance between the entrance (100) and the exit (101) of the processing channel (25) is substantially equal to or greater than the depth of the lowermost point of the processing channel (25). Apparatus according to any one of the preceding claims, wherein the thickness of the processing channel is about 2.0mm, preferably for use with photosensitive paper material (21), or is about 2.54mm, preferably for use with photosensitive film material (21).

Inventors: MANICO JOSEPH ANTHONY, PATTON DAVID LYNN, PICCININO RALPH LEONARD, ROSENBURGH JOHN HOWARD, MANICO, JOSEPH ANTHONY, PATTON, DAVID LYNN, PICCININO, RALPH LEONARD, ROSENBURGH, JOHN HOWARD, MANICO, JOSEPH ANTHONY, C/O EASTMAN KODAK COMP., PATTON, DAVID LYNN, C/O EASTMAN KODAK COMP., PICCININO, RALPH LEONARD, C/O EASTMAN KODAK COMP., ROSENBURGH, JOHN HOWARD, C/O EASTMAN KODAK COMP.
Applicants: EASTMAN KODAK CO, EASTMAN KODAK COMPANY
Application year: 1994
Main classification: G03D5
IPC codes: G03D3, G03D5